Negative pressure therapy has been utilized for the treatment of a variety of wounds by medical practitioners. Conventional negative pressure bandages are generally large in size and often require the use of complicated equipment such as suction pumps, vacuum pumps and complex electronic controllers to apply a negative pressure within the bandage to draw exudates and fluids away from the wound to a remote collection container. Typically, negative pressure therapy involves other associated equipment, such as the exudates/fluid collection canisters, liquid transporting conduits, and pressure regulators/transducers/sensors. As a result, negative pressure bandages and related equipment tends to be bulky and relatively costly. Such complexity typically requires professional placement of the bandage and connection to the pump and collection canister, followed by consistent, regular patient supervision and monitoring. Generally, negative pressure bandages are applied for approximately two days, at which time the bandage must be removed and replaced by professional technicians.
The rising costs of healthcare and of medical devices, such as negative pressure bandages, provide incentive to develop less expensive equipment, and procedures that are more easily utilized to reduce the costs associated with the use of negative pressure therapy while improving on the effectiveness of the therapy. Simplification of the procedures and the equipment can allow in-home use of such therapies with a minimum of professional supervision and monitoring of the patients. Furthermore, patients continue to demand devices that are more easily portable to allow travel and mobility while utilizing the therapy.
Conventional applications of negative pressure therapy to wound sites typically incurs the cutting of a porous foam pad to fit into the wound, followed by an application of an adhesive surgical drape over the pad and wound site to seal against the skin of the patient around the wound site. The fluids and exudates from the wound can be removed from the bandage to a remote location through an application of a vacuum to a connector fitted into the adhesive surgical drape, such as is shown in U.S. Pat. No. 5,636,643, granted on Jun. 10, 1997, in U.S. Pat. No. 5,645,081, granted on Jul. 8, 1997, and in U.S. Pat. No. 7,216,651, granted on May 15, 2007, all of which were issued to Louis Argenta. Alternatively, the foam pad can be utilized as a storage reservoir by incorporating a hydrophobic filter at the connector to prevent the fluids from leaving the bandage, as is reflected below in greater detail. Negative pressure therapy is provided commercially by at least KCI, Smith & Nephew, Kalypto, Medela, Mepilex and Convatec. An earlier negative pressure wound therapy embodiment is disclosed in U.S. Pat. No. 4,969,880, issued to David S. Zamierowski on Nov. 13, 1990.
The application of conventional negative pressure bandages to certain parts of the body presents substantial difficulties in maintaining a seal against the skin around the wound. Without the negative pressure bandage being sealed against the skin of the patient, the negative pressure system will not operate. Certain body parts, such as heels, ankles and toes present a multi-faceted skin surface against which the negative pressure bandage must seal. Conventional practices with the negative pressure bandages, such as are described below, require the planar bandages to be cut, shaped and compromised with respect to the sealing portion of the bandage to fit against the contoured body part.
In U.S. Pat. No. 7,615,036, granted to Ashok Joshi, et al on Nov. 10, 2009, a negative pressure bandage is disclosed in which the bandage has a housing that is sealed to the body surface of the patient and defines a liquid retention chamber coupled to a vacuum source to apply a negative pressure on the liquid retention chamber so that the exudates and fluids are drawn into an absorptive material within the liquid retention chamber. This liquid retention chamber is located adjacent to the wound from which the exudates and fluids are removed.
Improvements to negative pressure wound therapy devices can be found in U.S. Patent Publication No. 2009/0299251 of John Buan published on Dec. 3, 2009, to enhance the sealing of the bandage to the body surface of the patient. In this negative pressure wound therapy device, a vacuum is applied to a collection chamber in which an absorptive pad is disposed to collect the exudates and fluids drawn away from the wound by the vacuum (negative pressure). To enhance the connection of the tubing extending between the vacuum pump and the negative pressure therapy device, an extended length connector is disclosed, which will accommodate connection when ace wrap or other coverings are applied to the exterior of the bandage.
In U.S. Pat. No. 7,361,184, granted on Apr. 22, 2008, to Ashok Joshi, an attempt to provide a self-contained negative pressure wound therapy device is provided so that the device does not require connection to a remote vacuum source. In this negative pressure wound dressing, an absorptive pad is also disposed in the fluid collection chamber, which is located adjacent to the wound, the negative pressure drawing the exudates and fluids away from the wound into the absorptive pad. Several early embodiments of negative pressure bandages can be found in U.S. Pat. No. 5,636,643, granted to Louis Argenta, et al on Jun. 10, 1997, all of which, however, utilize a single chamber configuration in which a vacuum is applied to the fluid collection chamber and the exudates and fluid is drawn away through tubing to a remote pump and fluid retention chamber.
It would be desirable to provide a contoured negative pressure bandage that will be adapted to be affixed to a specific contoured body part to remove exudates and fluid from a wound located on that contoured body part.